Sound installation for interior, Experience and suggestions Options

[Mcraneiowa]

I purchased a couple rolls of Farman adhesive backed sound material with the aluminum foil top. Curious what everybody’s thoughts are for using this in the interior, on the floors and behind the back panel.

Thinking simply roll/press it down with a roller and then tape the seams. Are there other ways or material that people prefer to use as I keep thinking of the moisture that at some point will likely get under the sound insulation material even if I tape it.

FYI, I did replace the floors then coated entire floor top and bottom with Por15, followed up with paint so I’m starting with a very nice surface. I know I can put this down and will be fine for probably at least 15 or 20 years but I would like to think I could make it last longer so the next guy won’t have to worry about rust. Like to know what others have done and what their experiences are.

[bbrock]

Keep in mind that different sound deadening materials are needed to dampen or insulate different types of sound. There is a reason the factory installed tar sheets on the floor and a thick tar-covered fiber mat on the firewall. The foil faced, butyl based mats most commonly used are intended to dampen vibrations. There's a great demo of how that works 30 seconds into this video: https://www.youtube.com/watch?v=P4ylKyoY_oU Those mats work great on floors and inside door skins to eliminate drumming and resonance. As was mentioned, put a couple strips of that inside your doors and you will get that solid German "thunk" when you shut the door instead of the cheap tinny ring of untreated doors. Those mats aren't going to help as much on the firewall although they'll help.

For deadening exhaust and engine noise, you want more of an insulating material. Open cell foam and fiber mats are often used. That's really what you want on the firewall in addition to a vibration dampener. Don't overlook the importance of tight weatherstrip for sound either. Sealing the rear window was already mentioned, but sealing around side windows helps too.

As far as moisture trapping. I think it is a non-issue with the modern butyl based mats. When those are rolled on properly, you are really adding a thick layer of mastic tightly bonded to the surface which should increase moisture protection rather than trap it. It's very different from the original tar.